After more than seven years as prosecutor at the international criminal court – with no convictions, or even completed trials – Luis Moreno-Ocampo still does not understand that it is the job of a prosecutor to bring charges, and the job of a court to decide whether or not the defendant is guilty.

We saw this from Moreno-Ocampo's article for the Guardian last month about the president of Sudan, Omar al-Bashir. Although the prosecutor said that Bashir had "officially denied the genocide, the rapes, the camp conditions and his responsibility for them", Moreno-Ocampo alleged that "Bashir's forces continue to use different weapons to commit genocide". Except that "alleged" was not a word he used.

Moreno-Ocampo really ought to know better. In May, judges at the court expressed "the strongest disapproval" of a "misleading and inaccurate" media interview given by one of his three deputies. Béatrice Le Fraper du Hellen was found to have spoken about another case "in a manner that is prejudicial to the ongoing proceedings". The judges deprecated remarks that "seriously intruded" on their own role. Within three weeks she had left the court and her post remains vacant.

Le Fraper du Hellen had given an interview to a website devoted to the trial of the alleged Congolese warlord Thomas Lubanga. In it, Moreno-Ocampo's deputy described her boss as "a very accurate and fair prosecutor" and said of the defendant: "Mr Lubanga is going away for a long time."

The court let Le Fraper du Hellen off with a caution, adding that "if objectionable public statements of this kind are repeated" it would "not hesitate to take appropriate action against the party responsible".

That ruling was cited at the end of last month in a submission by lawyers for two Sudanese groups opposed to Bashir's arrest. Sir Geoffrey Nice QC and Rodney Dixon asked the court to review Moreno-Ocampo's remarks, arguing that the Guardian article might make it more difficult for the court to "render dispassionate adjudication".

This submission was rejected as inadmissible by a judge on 6 August. But there has been no ruling yet on a separate complaint filed by a Quebec-based lawyer appointed by the court to represent Bashir's interests.

Michelyne St-Laurent argued that Moreno-Ocampo's comments were even more serious than those his deputy had made in the Lubanga case. St-Laurent was "shocked by their falsity, both in fact and law". They made a fair trial impossible.

Moreno-Ocampo had led people to believe that Bashir was guilty of genocide, the lawyer said, denying the defendant's presumption of innocence. In her view, the prosecutor had stirred up hatred and invited the Sudanese people to stage a revolt against their head of state.

St-Laurent also accused Moreno-Ocampo of breaching his oath of impartiality, threatening peace efforts in Sudan and undermining the credibility of the court. She asked the court to condemn the prosecutor's article and take "all appropriate measures" against him.

If Moreno-Ocampo had spent less time grandstanding and more time in court, he might have concluded his first case by now. Instead, three judges ordered an immediate halt to Lubanga's trial on 8 July, declaring it an abuse of the process of the court and deciding on 15 July that the defendant had to be released. The order was suspended pending the prosecutor's inevitable appeal.

What persuaded the judges, headed by Sir Adrian Fulford, to take this radical step? It was because the prosecutor had failed to comply with repeated orders to give defence lawyers the name of an intermediary who had assisted the prosecution by liaising with witnesses. Some intermediaries are alleged to have helped witnesses fabricate statements.

Protective measures for the intermediary were a matter for the judges, they said. "The prosecutor now claims a separate authority which can defeat the orders of the court, and which thereby involves a profound, unacceptable and unjustified intrusion into the role of the judiciary."

Even if the prosecutor's appeal is successful, he faces a fine or suspension for non-compliance with the court's orders. Swapping places with Lubanga in the dock might finally help Moreno-Ocampo to understand that it's for prosecutors to prosecute and judges to judge.